1. Field Of The Invention
This invention relates to the production of sponge goods, especially crackers, having a low sodium content.
2. Description Of The Prior Art
As described in the U.S. Ser. No. 584,868 filed Feb. 29, 1984, now abandoned, in the production of sponge goods, such as soda crackers, sodium bicarbonate serves a dual function of: 1) neutralizing the acids produced by fermentation in production of the sponge and, 2) leavening the sponge-good dough prior to and during baking. The yeast-leavened sponge contains a considerable amount of acid which is developed by the yeast and by bacteria during fermentation. Sponge formation is followed by production of the sponge-good dough. Conventionally, the acid in the sponge is neutralized by adding sodium bicarbonate when the dough is mixed.
Conventional processes for the production of soda crackers are disclosed in U.S. Pat. Nos. 1,803,588 and 2,288,118 and in Johnson et al, Encyclopedia of Food Technology, The AVI Publishing Company, Inc., Westport, Conn., Vol. 2, pages 113-114 (1974), by Matz, Samuel in Cereal Technology, The AVI Publishing Company, Inc., Westport, Conn., pages 80-82 (1970), and by Matz, Cookie and Cracker Technology, The AVI Publishing Company, Inc., Westport, Conn., pages 137-142 (1968). A soda cracker produced by this method typically contains about 194 mg total sodium per 14.2 gm serving. About 20 to 25% of this total sodium is due to the use of sodium bicarbonate. Medically, it is considered essential that persons suffering from vascular diseases, coronary diseases, and liver diseases, be restricted to a low sodium diet.
Many compositions have been developed as a replacement for common table salt, or sodium chloride, for use in low sodium diets. Salt substitute compositions are disclosed in U.S. Pat. No. Re. 27,981; U.S. Pat. Nos. 2,601,112; 2,824,008; and 3,505,082. In the compositions of these patents, potassium chloride is used as a replacement for sodium chloride. Other ingredients are added to mask the bitter taste of the potassium ion and to minimize caking and dusting. The beneficial effect of including potassium in the diet is taught in U.S. Pat. No. 4,216,237 and in Russian patent 257,399. In U.S. Pat. No. 4,216,237 the bitter taste of the potassium ion is masked with a water-soluble, carbohydrate foodstuff ingredient. Potassium chloride, it is disclosed, is prone to ulcerate the intestinal tract, in addition to being unpalatable. Substantially equal portions of bicarbonate, citrate, and diphosphate are used to achieve a better balance of anions more closely related to natural potassium sources. Approximately 1/4 to 1/2 of the potassium salt ingredient is comprised by the chloride. In Soviet patent 257,399, potassium chloride is used in a two-to-one ratio with lithium chloride to improve the curing properties of dietetic bread or rolls. The taste of the products, it is disclosed, is the same as with sodium chloride and the harmful effects of sodium chloride are avoided. While replacement of sodium chloride with potassium chloride can be beneficial to the health, as indicated in these patents, it would not serve the function of neutralizing the acids produced in forming a sponge, and it would not leaven the sponge-good dough. Additionally, sodium chloride contributes flavor to a cracker or other sponge good. In producing a low sodium sponge good, it would be desirable to eliminate other sources of sodium to enable retention of some sodium chloride for its flavoring characteristics.
While sodium bicarbonate is the most widely used chemical leavening agent, many other compositions for producing carbon dioxide gas in foods without the use of sodium bicarbonate are known. Baking powder compositions which contain ammonium carbonate or ammonium bicarbonate are disclosed in U.S. Pat. Nos. 150,844; 174,890; 235,615; and 1,865,938. The carbonate of barium is considered to be poisonous in U.S. Pat. Nos. 331,541 and 331,542. The carbonates of calcium, magnesium and strontium are used in the baking powder compositions of the latter two patents. The carbonates of calcium are also utilized in the baking powders of U.S. Pat. Nos. 150,844 and 328,364. The carbonates of magnesium are present in the baking powders of U.S. Pat. Nos. 315,830; 315,831; 315,832; and 328,364. The carbonate or bicarbonate of potassium is present in the baking powder compositions of U.S. Pat. No. Re. 2,597, U.S. Pat. No. Re. 2,979, and U.S. Pat. Nos. 14,722; 96,994; 150,844; 174,890; 235,615; and 673,057. According to U.S. Pat. No. 235,615, the bicarbonate is preferred over the carbonate for raising bread because less lactate is required to react with the bicarbonate. In U.S. Pat. No. 422,464, it is taught that ammonium carbonate is used to prevent a baking soda comprising cream of tartar and sodium bicarbonate from becoming hard. However, according to U.S. Pat. No. 422,464, the carbonate of ammonium is considered to be objectionable as a food.
Effervescing salt compositions which utilize carbonates for producing carbon dioxide are disclosed in U.S. Pat. Nos. 1,450,865 and 2,984,543. The carbonates or bicarbonates of sodium, potassium, ammonium, calcium or magnesium may be used in the compositions of U.S. Pat. No. 1,450,865. In U.S. Pat. No. 2,984,543, the effervescing salt may contain potassium or lithium bicarbonates or calcium, magnesium, or organic carbonates. However, in these effervescing salt compositions and in the baking powder compositions, an acid is included for reaction with the bicarbonate or carbonate for producing the carbon dioxide. These compositions would be unsuitable for use in producing a sponge-good dough because they would not serve the dual function of leavening the sponge-good dough and neutralizing the acids which are produced during formation of the sponge.
The addition of an alkaline carbonate as a neutralizer and as a leavening agent for a "prepared flour" is taught in U.S. Pat. No. 1,428,628. Lactic acid which is present in sour milk or butter milk of the prepared flour is neutralized by the alkaline carbonate. Bicarbonate of soda, however, is the only carbonate disclosed in the patent.
The use of carbonates, other than sodium bicarbonate in the production of baked goods is disclosed in British patent Nos. 1,085 of 1883 and 335,214, U.S. Pat. No. 2,970,915 and as early as 1796 in American Cookery, by Amelia Simmons, reprint by Martin Rywell, Buck Hill Associates, Johnsburg, N.Y. 12843, pps. 30-31 (1966). The addition of iron and manganese carbonates to bread and biscuits for medicinal purposes is disclosed in British patent No. 1,085 of 1883. Magnesium and/or calcium carbonates are taught as acid-neutralizing constituents in British patent 335,214 for dough or flour compositions which contain persulphates and bromates. Calcium carbonate is disclosed as a bread improver in U.S. Pat. No. 2,970,915. In American Cookery, recipes for honey cake and cookies include pearl ash, an impure potassium carbonate product obtained by partial purification of potash from wood ashes. Replacement of sodium bicarbonate with potassium carbonate to achieve sodium reduction in the final baked product is not taught by any of these references.
The preparation of a health bread with potassium carbonate and ammonium carbonate as a leavening agent is taught in U.S. Pat. No. 2,228,729. The potassium carbonate, it is disclosed, results in a bread which is free of greenish color or hue and possesses a fine whitish interior. The ammonium and potassium carbonates are added to a sponge which contains approximately 40% or more eggs. The large percentage of eggs, it is disclosed, creates a large expanding force upon heating thereby reducing the usual amount of chemical leavening agents needed for expansion. Although a sponge is produced, fermentation is not disclosed in the patent. Additionally, the degree of expansion needed in the production of the bread would be unacceptable in the production of crackers.
The use of alkaline carbonates, other than those of sodium, as a leavening agent or neutralizing agent in the production of baked goods, is also disclosed in U.S. Pat. Nos. 317,821; 1,913,044; 2,070,922; and 2,394,791, and in Food Materials & Equipment, page 18, (March 1946). Treating a sponge to neutralize its acidity, to leaven it and to obtain a low-sodium cracker is not disclosed in these references. In U.S. Pat. No. 317,821, the acid or disulfate of potash with carbonates or bicarbonates of potash is used as a replacement for tartaric acid in the production of bread, cakes, biscuits, and the like. In U.S. Pat. No. 1,913,044, a bicarbonate or carbonate of either sodium or potassium is reacted with manganese succinate to promote oxidation of the coloring matter in a bread dough. Calcium carbonate is taught as a replacement for sodium bicarbonate in the pastry industry in the Food Materials & Equipment article. In U.S. Pat. No. 2,070,922, hydrogen peroxide is used as a leavening agent in the production of waffles, griddle cakes, crackers, and the like. Alkaline metal carbonates are used to stabilize the hydrogen peroxide and to make the formulation alkaline at a pH of about 8 to 10. Pre-neutralization of starch for various wafer or waffle batters with calcium carbonate is taught in U.S. Pat. 2,394,791. The calcium carbonate replaces a portion of the sodium bicarbonate, the sodium bicarbonate being retained to obtain sufficient leavening action.
Treatment of a fermented dough with a carbonate other than sodium is disclosed in U.S. Pat. No. 2,032,442. In the process of this patent, a heat-decomposable ammonium compound, such as a carbonate of ammonium, is applied to the surface of a fermented dough. Subsequent baking releases ammonia which browns the surface of the bread, rolls, and like products. Mixing of the ammonium carbonate with the fermented dough to distribute it substantially uniformly throughout the dough to achieve neutralization of acids produced during fermentation is not disclosed.
Baker, U.S. Pat. No. 3,297,449 describes improvements in packaged dough compositions and especially those kept under refrigeration prior to use. The doughs disclosed in Baker are not sponge goods and do not undergo a fermentation step. Rather, the doughs in Baker contain a chemical leavening system composed of one or more leavening acids and an alkaline substance capable of releasing carbon dioxide upon reaction with the leavening acid. Baker discloses that sodium acid pyrophosphate has been found to be especially well suited to function as the leavening acid in such chemical leavening systems. Accordingly, Baker continues, so far as leavening of the dough is concerned, the system of sodium acid pyrophosphate and baking soda (sodium bicarbonate) is eminently satisfactory. However, according to Baker, this combination of sodium acid pyrophosphate and sodium bicarbonate has the severe disadvantage that, during storage over a long period, these components tend to react together to form disodium orthophosphate dodecahydrate, which deposits in the dough in the form of glassy monoclinic crystals which resemble broken glass, thereby leading many housewives to fear that the dough is contaminated. Baker teaches that the formation of crystals of disodium orthophosphate dodecahydrate in the dough can be reduced by substituting potassium for sodium in the dough by using potassium bicarbonate, or less desirably potassium carbonate, in place of the sodium bicarbonate in the leavening agent. Thus, the teaching of Baker is that, in a chemically leavened dough in which the leavening agent comprises sodium acid pyrophosphate and sodium bicarbonate, the tendency for objectionable crystals to be formed in the dough can be reduced by replacing part of all of the sodium bicarbonate with potassium carbonate. The avoidance of crystals of disodium orthophosphate dodecahydrate is only purpose for which Baker teaches replacement of sodium bicarbonate with potassium bicarbonate, or less desirably potassium carbonate.
U.S. Pat. No. 4,379,174 to Umina discloses a method of controlling leavening in a bakery mix to be used at various elevations comprising packaging all but one of the ingredients (preferably sodium bicarbonate) which produce leavening in a separate package from that containing the remaining ingredients of the baking mix, the package containing this one ingredient being provided with indicia at various levels to indicate the proper amount of sodium bicarbonate or other leavening ingredient for a selected elevation to be added to the remaining ingredients of the baking mix. The passage at column 3, lines 55-59 of this patent, states that "the component of the bakery mix which is isolated from other components of the bakery mix may be other potential gas-liberating materials, such as other edible carbonates or bicarbonates, e.g., ammonium bicarbonate"; there is no mention of potassium, much less of potassium carbonate or bicarbonate in this passage.
The use of alkaline carbonates, other than sodium bicarbonate, in fermented doughs for the production of various baked goods, is disclosed in U.S. Pat. Nos. 2,033,099; 2,137,027; 3,108,878; and 4,044,155. In the processes of these patents the alkaline carbonate is added with the yeast and is present during fermentation. Breads, rolls, buns, and the like are produced from these yeast leavened doughs. The production of soda crackers is not disclosed. In U.S. Pat. No. 2,033,009, an alkaline salt is added to the yeast food to keep it alkaline until it reaches the fermentation stage, whether in the dough or in the sponge. Calcium carbonate or magnesium carbonate are disclosed as the preferred alkaline salts because of their slow solubility. In U.S. Pat. No. 2,137,027, a yeast sponge is buffered with ammonium carbonate or calcium or magnesium carbonates. In U.S. Pat. No. 3,108,878, a calcium carbonate buffer is added with yeast to a soy flour dough composition. In U.S. Pat. No. 4,044,155, a non-fat dry milk substitute for incorporation into yeast-leavened doughs, is prepared by mixing deproteinized whey, an ammonium compound such as ammonium carbonate or bicarbonate, and a protein supplement. A basic material, such as a carbonate or bicarbonate of sodium, potassium, calcium, or magnesium, is optionally added to control the pH of the substitute and to at least partially neutralize the deproteinized whey.
Calcium carbonate is taught as a buffering agent for a liquid yeast brew in U.S. Pat. No. 3,490,916. The brew may be used to form a yeast leavened dough, which may be a cracker or soda cracker composition. The use of calcium carbonate to neutralize the acids present in a sponge and to leaven the fermented dough is not disclosed. Furthermore, calcium carbonate is not sufficiently soluble in water to uniformly neutralize the acids in a sponge or to leaven a sponge dough substantially uniformly.
U.S. Pat. No. 1,633,872 discloses ammonium bicarbonate as a substitute for baking soda in the production of an unsalted cracker. The use of ammonium bicarbonate instead of sodium bicarbonate as the means of raising the dough, it is disclosed, eliminates the soda flavor and improves the color of the cracker. A relatively rapid fermentation time of four to five hours is used before the ammonium bicarbonate is added to the sponge dough. Adding sufficient ammonium bicarbonate to neutralize acids produced during the fermentation is not disclosed. According to U.S. Pat. No. 1,633,872, if too large a proportion of ammonium bicarbonate is used, a yellow objectionable color develops in the cracker.
In using ammonium bicarbonate alone as a replacement for sodium bicarbonate, neutralization of acids produced during fermentation becomes a problem. As disclosed in U.S. Pat. No. 1,633,872, the ammonium bicarbonate is entirely volatilized in the baking operation. The release of both ammonia and carbon dioxide makes pH control of the final product difficult. Furthermore, it has been found that replacement of sodium bicarbonate with ammonium bicarbonate in the production of a soda cracker, does not result in a uniform laminar cell structure. Large cells and tight areas are obtained with ammonium bicarbonate. The cracker is too tender and has both flat and raised or bubbled portions. Accordingly, ammonium bicarbonate alone is not a suitable replacement for sodium bicarbonate in the production of an acceptable low sodium soda cracker.
Potassium bicarbonate has been used as a component in leavening mixtures for baked products intended to be consumed in sodium-free diets. However, as disclosed by Matz in Cookie and Cracker Technology (1968) at page 77, potassium bicarbonate is very hygroscopic and tends to impart a bitter flavor to the foods in which it is used. Crackers are baked to a low moisture content and their crispness gives a snap or crunch upon eating. The presence of a highly hygroscopic material in a cracker would tend to be deleterious to the achievement of these sensory properties. Additionally, potassium bicarbonate is expensive. Matz teaches away from the use of carbonates because their very high alkalinity, compared to the alkalinity of sodium bicarbonate, tends to result in localized areas of very high alkalinity which is formed as the granules dissolve in the dough. These localized areas, it is disclosed, result in reactions which lead to undesirably colored and flavored products. In producing a laminated product, these localized areas generally appear as dark streaks in the baked product.
The present invention provides a process for the production of sponge goods, especially crackers, having a crisp texture, a non-bitter taste, a pleasant mouth feel and a substantially uniform laminar cell structure without using sodium bicarbonate. Thus, substantial sodium reduction can be achieved while retaining sodium chloride for its flavoring characteristics. The baked products have a uniform brown color on their surfaces, are of substantially uniform pH throughout, and are devoid of hot-spots or dark streaks caused by localized areas of carbonate leavening agents.
Food Science Technology Abstracts, 1980, No. 719 584, V. A. Patt et al., "Process for preparing wheat samples for breadmaking", describes a process for making bread containing flour, water and an alkali metal carbonate, which can be potassium carbonate. Brot und Gebaeck, 18th Year 1964, Book 3, pages 41-48, describes a process in which potassium carbonate is used in the production of a "Dutch breakfast cake". Neither of these documents describes the use of potassium carbonate as a leavening agent to produce sponge goods having a pH within the range produced by the method of this invention.
Under current Food and Drug Administration proposals, a "low sodium" baked good, which includes sponge goods, unfermented type crackers, cookies and cakes, has a sodium content of from 35 to 140 mg. Na.sup.+ per serving, while a "very low sodium" baked good has a sodium content of less than or equal to 35 mg. Na.sup.+ per serving. Also, a "no-sodium" baked good has a sodium content of less than or equal to 5 mg. Na.sup.+ per serving. According to FDA proposed rules, products which contain not more than 20% in excess of the value stated for sodium declared in the label are considered to be properly labeled. "Very low-sodium" products and "no-sodium" products may accordingly contain up to 42 mg. per serving and up to 6 mg. per serving, respectively. The weight of a "serving" depends upon the type of baked good. As used herein, a serving is 14.2 g. (1/2 oz.) for crackers of the fermented and unfermented-types, and 28.35 g. (1 oz.) for cookies and pretzels. The present invention provides a process for reducing the sodium content of sponge goods to a "low sodium", "very low sodium" or "no sodium" level as defined above for each type of sponge good. The sodium content is based upon the final baked product (i.e., the serving) and includes sodium from topping salt (sodium chloride) as well as from salt within the final product.
The aforementioned copending application Ser. No. 584,868 discloses replacement of the sodium bicarbonate in sponge-good doughs with potassium carbonate, the amount of potassium carbonate used being sufficient to obtain a pH in the baked cracker of from about 7.0 to about 8.0.
Application Ser. No. 773,127, filed Sept. 6, 1985 abandoned in favor of U.S. Ser. No. Oct. 6, 1987 now U.S. Pat. No. 4,859,473 as a continuation-in-part of the aforementioned copending application Ser. No. 584,868 filed Feb. 29, 1984, now abandoned, discloses a leavening composition for chemically leavening baked goods, the leavening composition comprising from about 40 to about 80 percent by weight of ammonium bicarbonate, from about 30 to about 10 percent by weight of potassium carbonate, and from about 30 to about 10 cent by weight of an edible acidic component capable of reacting with the potassium carbonate to liberate dioxide, the percentages being based upon the weight of the bicarbonate, potassium carbonate and the acidic component on an anhydrous basis.
The aforementioned application Ser. No. 773,127 also states that the choice of a leavening system for a low-sodium unfermented cracker, or other unfermented or chemically leavened baked goods, involves consideration of a number of properties desired in the final cracker, including sodium content, oven spring, browning (the production of a brown color in the baked cracker), and the pH of the baked cracker. Of the acidic components available for use in chemical leavening systems, calcium phosphate monobasic is usually preferred since it not only acts as the acidic component of the leavening system but also promotes browning of the cracker. Increasing the proportion of ammonium bicarbonate in the leavening system increases oven spring, as already noted, but may affect the pH, and hence the taste, of the final product, since ammonium bicarbonate is less alkaline than potassium carbonate. Potassium carbonate tends to produce less oven spring than ammonium bicarbonate, but its more alkaline character is useful in increasing the pH of the final cracker to within the desired range.
As mentioned above, the aforementioned application Serial No. 584,868 filed Feb. 29, 1984, now abandoned teaches that sponge goods having reduced sodium contents can be prepared by replacing part or all of the sodium bicarbonate, conventionally used in the dough-up stage of the process for preparing sponge goods, with potassium carbonate. However, it has been found that, if potassium carbonate alone is used to replace the conventional sodium bicarbonate, difficulties are encountered if the lay time of the dough-up stage (the period from the time at which the dough ingredients are mixed to the time at which the finished dough is laminated and baked) becomes protracted, as may happen, for example, in commercial production where mechanical faults in the machinery used for lamination, baking and packing may require the processing of a batch of formed dough to be delayed. More specifically, it has been found that, if a dough containing only potassium carbonate is allowed to stand for an extended period, the pH of the dough tends to vary, and this variation in pH of the dough affects both the oven spring and the taste of the final cracker.
It has now been found that the problems encountered when using potassium carbonate as the leavening agent in sponge goods can be reduced or eliminated is the potassium carbonate is used in admixture with potassium bicarbonate.